How to track config files of submodules in Git?

Question

In Git, how can I organize work to track local config files of a library, which is a git submodule?

In details:

the library has normal files

Answer 1

When using a submodule, you should avoid making any modification because of the container (here: the project using the lib), because it will create a new revision on the history of the submodule.

It would be possible, for instance, for the lib, to reference config template files that can be the base for :

• default value config files generation (the lib has a default value file archived, which can be used to generate a complete but not tracked config file)
• or a custom config file generation (the project has its own config file values, and use it to generate at the same place within the lib a non-tracked config file)

A "config file template with tokenized values in it, and a script transforming that config.template file into a private (and ignored) config file" is the approach I suggested in this SO question about merge management.

Other more general advices on config files can be found in this SO question.